Skin color is principally determined by the concentration of melanin produced by the melanocytes. Synthesis of melanin starts with the conversion of the amino acid-L-tyrosine to 3,4-dihydroxyphenolalanine (L-DOPA) which, in turn, is oxidized to yield dopaquinone by tyrosinase (Kubo, I. et al. J Nat Prod 1994, 57, 545-551; Sakuma, K. et al. Arch Pharm Res 1999, 22, 335-9; Yang, F. and Boissy, R. E. Pigment Cell Res 1999, 12, 237-45). The catalytic action of the enzyme tyrosinase constitutes the rate-limiting step for melanin biosynthesis (Hearing, V. J. and Jimenez, M. Pigment Cell Res. 1989, 2, 75-85). Widely distributed in the plant and animal kingdom, tyrosinase is a multifunctional copper-containing enzyme (Shimizu, K. et al. Planta Med 2000, 66, 11-5) that mediates the coloring of skin, hair and eyes in animals as well as the familiar browning of fruits and vegetables (Kubo, I. et al. Bioorg Med Chem 2000, 8, 1749-55; Perez-Gilabert, M. and Garcia-Carmona, F. Biochem Biophys Res Commun 2001, 285, 257-61). Tyrosinase is also involved in the abnormal accumulation of melanin pigments (hyperpigmentation) on the skin or nails of people (Hearing, V. J. and Jimenez, M. Pigment Cell Res. 1989, 2, 75-85). Consequently, tyrosinase inhibitors such as kojic acid and albutin have been employed as important constituents of cosmetic products for skin lightening, skin whitening, and depigmenting hyperpigmentation and related conditions (Masamoto, Y. et al. Biosci Biotechnol Blochem 2003, 67, 631-4). More broadly, the utility of tyrosinase inhibitors has expanded in recent years to the food industry as well as medical products.